Known equipment such as propellers, centrifugal turbines, spiral centrifuges, etc. encounter well known difficulties as to the handling of fluids as soon as extreme conditions are approached, particularly in the case of a considerable increase in rotational speed. The minimum operating limits of such equipment is related to the suction pressure. Whenever the pressure in a liquid drops below the vapor pressure corresponding to its temperature, the liquid will vaporize, resulting in cavitation. To avoid cavitation, it is necessary to maintain a required net positive suction head (NPSH) which is equivalent to the total head of liquid at the equipment centerline less the vapor pressure. The use of the Archimedes screw having an increasing diameter over the longitudinal length of the screw, in the form of a discharge corkscrew, is the best known remedy to avoid cavitation of liquids or the exaggerated expansion of gases in the inlet of the equipment.